Find the mean and variance for the data 6, 7, 10, 12, 13, 4, 8, 12

Solution:

The given data is 6, 7, 10, 12, 13, 4, 8, 12.

Mean of the data is given by

x = (∑⁸_{i = 1}x_i)/n

= (6 + 7 + 10 + 12 + 13 + 4 + 8 + 12)/8

= 72/8

= 9

The following table is obtained from the given above data

xi	(xi - x)	(xi - x)2
6	-3	9
7	-2	4
10	1	1
12	3	9
13	4	16
4	-5	25
8	-1	1
12	3	9
		74

Variance of the data

(σ²) = 1/n ⁸∑_{i = 1}(x_i - x)²

= 1/8 × 74

= 9.25

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NCERT Solutions Class 11 Maths Chapter 15 Exercise 15.2 Question 1

Find the mean and variance for the data 6, 7, 10, 12, 13, 4, 8, 12

Summary:

The mean and variance for the given data are 9 and 9.25